1 files changed, 45 insertions, 0 deletions
diff --git a/3638/CH21/EX21.2/Ex21_2.sce b/3638/CH21/EX21.2/Ex21_2.sce
new file mode 100644
index 000000000..2539437db
--- /dev/null
+++ b/3638/CH21/EX21.2/Ex21_2.sce
@@ -0,0 +1,45 @@
+//Introduction to Fiber Optics by A. Ghatak and K. Thyagarajan, Cambridge, New Delhi, 1999
+//Example 21.2
+//OS=Windows XP sp3
+//Scilab version 5.5.2
+clc;
+clear;
+//given
+nf=1.51;//refractive index of film
+ns=1.50;//refractive index of substrate
+nc=1.0;//refractive index of cover
+d=4e-6;//thickness of film in m
+lambda0=0.6e-6;//Wavelength in m
+ne1=1.50862;//Corresponding effective refractive index for core
+ne2=1.5046;//Corresponding effective refractive index for cladding
+//Let A be the period of perturbation in m
+
+
+//Case (i):
+A=100e-6;
+K=2*%pi/A;
+k=0.598e2;//coupling coefficient in m^-1 (from previous example)
+T=2*%pi/lambda0*(ne1-ne2)-K;//Phase mismatch in m^-1
+y=sqrt(k^2+(T/2)^2);//Resultant of k and T in m^-1
+
+mprintf("\n For A=100 um:");
+P2max=(k/y)^2;//Maximum power that gets transferred between the modes
+mprintf("\n P2max= %.1e",P2max);
+L=%pi/(2*y);//Distance for maximum power transfer in m
+mprintf("\n L=%.1f um\n",L/1e-6);//Division by 10^(-6) to convert into um
+//The answers vary due to round off error
+
+
+//Case (ii):
+A=148e-6;
+K=2*%pi/A;
+k=0.598e2;//coupling coefficient in m^-1 (from previous example)
+T=2*%pi/lambda0*(ne1-ne2)-K;//Phase mismatch in m^-1
+y=sqrt(k^2+(T/2)^2);//Resultant of k and T in m^-1
+
+mprintf("\n For A=148 um:");
+P2max=(k/y)^2;//Maximum power that gets transferred between the modes
+mprintf("\n P2max= %.1e",P2max);
+L=%pi/(2*y);//Distance for maximum power transfer in m
+mprintf("\n L=%.1f mm",L/1e-3);//Division by 10^(-6) to convert into mm
+